Added berkeley segmentation dataset and windowed sphering (including two-level windowing,
so that the sphering filter is applied to a wider window than the final output)
No L2 norm for entropy loss, softmax scaling for entropy 2.5*0.875, entropy scaling 0.15,
global L1 scaling 0.5 (cifar-specific), L1 scaling 5,
12x12 berkeley window, 400 units, 11 ista iterations, 1 regularization iterations
learning rate 5e-3, minibatch size 10, 1000 epochs pretraining
decoding_feature_extraction_dictionary rows are fully normalized